Sheen occurs in open water such as near offshore platforms, in harbors, lakes canals or the like. Sheen may be due, for example, to natural seeps, offshore discharges (such as produced water, sump, or completion or workover fluids) and pipeline leaks or due to a chemical spill. It may also be caused by runoff from industrial locations to open water canals or rivers. It becomes necessary to collect samples of the sheen off the water in order to evaluate the cause of the sheen and develop a solution to prevent further sheen.
Collection of sheen samples, however, may be difficult using commonly available methods and apparatus. For example, the floor of a platform may be quite far above the surface of the water and the sheen, many times necessitating the need for a boat to collect samples. Sheen may also collect in areas which are difficult to reach, even by boat. Sheens are generally very thin layers, only microns thick. A common method of taking a sample is to dip a container into the water. However, taking a sample by a container causes the dissipation of the sheen and prevents the collection of enough volume necessary for analysis.
Some solutions to the container sampling problem is seen by using collection devices such, as glass plates and solvent pads, both of which are dipped into the sheen, Teflon drums, which are rolled in the sheen, Teflon tape, and polypropylene tape attached to a rake. Each of these has disadvantages, particularly when collecting from a platform or a boat on rough waters.